The generalized Kadanoff-Baym ansatz with initial correlations
Karlsson, D., van Leeuwen, R., Perfetto, E., & Stefanucci, G. (2018). The generalized Kadanoff-Baym ansatz with initial correlations. Physical Review B, 98(11), Article 115148. https://doi.org/10.1103/PhysRevB.98.115148
Published inPhysical Review B
©2018 American Physical Society
Within the nonequilibrium Green’s function (NEGF) formalism, the generalized Kadanoff-Baym ansatz (GKBA) has stood out as a computationally cheap method to investigate the dynamics of interacting quantum systems driven out of equilibrium. Current implementations of the NEGF-GKBA, however, suffer from a drawback: real-time simulations require noncorrelated states as initial states. Consequently, initial correlations must be built up through an adiabatic switching of the interaction before turning on any external field, a procedure that can be numerically highly expensive. In this work, we extend the NEGF-GKBA to allow for correlated states as initial states. Our scheme makes it possible to efficiently separate the calculation of the initial state from the real-time simulation, thus paving the way for enlarging the class of systems and external drivings accessible by the already successful NEGF-GKBA. We demonstrate the accuracy of the method and its improved performance in a model donor-acceptor dyad driven out of equilibrium by an external laser pulse. ...
PublisherAmerican Physical Society
Publication in research information system
MetadataShow full item record
Related funder(s)Academy of Finland
Funding program(s)Postdoctoral Researcher, AoF
Additional information about fundingD.K. acknowledges the Academy of Finland for funding under Project No. 308697, and the Finnish Grid and Cloud Infrastructure for computational resources (urn:nbn:fi:researchinfras-2016072533). G.S. and E.P. acknowledge EC funding through the RISE Co-ExAN (Grant No. GA644076). E.P. also acknowledges funding from the European Union project MaX Materials design at the eXascale H2020-EINFRA-2015-1, Grant Agreement No. 676598 and Nanoscience Foundries and Fine Analysis-Europe H2020-INFRAIA-2014-2015, Project No. 654360. ...
Showing items with similar title or keywords.
Developments in many-body theory of quantum transport and spectroscopy with non-equilibrium Green's functions and time-dependent density functional theory Uimonen, Anna-Maija (University of Jyväskylä, 2015)The problem of quantum dynamics in open systems has gained attention in recent decades and not the least due to the advances made in quantum transport in molecular systems. The main motivation behind quantum transport ...
Many-body Green's function theory of electrons and nuclei beyond the Born-Oppenheimer approximation Härkönen, Ville J.; van Leeuwen, Robert; Gross, E. K. U. (American Physical Society, 2020)The method of many-body Green's functions is developed for arbitrary systems of electrons and nuclei starting from the full (beyond Born-Oppenheimer) Hamiltonian of Coulomb interactions and kinetic energies. The theory ...
Approximate energy functionals for one-body reduced density matrix functional theory from many-body perturbation theory Giesbertz, Klaas J. H.; Uimonen, Anna-Maija; van Leeuwen, Robert (Springer, 2018)We develop a systematic approach to construct energy functionals of the one-particle reduced density matrix (1RDM) for equilibrium systems at finite temperature. The starting point of our formulation is the grand potential ...
Partial self-consistency and analyticity in many-body perturbation theory: Particle number conservation and a generalized sum rule Karlsson, Daniel; van Leeuwen, Robert (American Physical Society, 2016)We consider a general class of approximations which guarantees the conservation of particle number in many-body perturbation theory. To do this we extend the concept of derivability for the self-energy to a larger class ...
Electronic transport in molecular junctions : The generalized Kadanoff–Baym ansatz with initial contact and correlations Tuovinen, Riku; van Leeuwen, Robert; Perfetto, Enrico; Stefanucci, Gianluca (AIP Publishing, 2021)The generalized Kadanoff–Baym ansatz (GKBA) offers a computationally inexpensive approach to simulate out-of-equilibrium quantum systems within the framework of nonequilibrium Green’s functions. For finite systems, the ...